Once more unto the open thread…
Ian @ 49, thanks for the tip, is there a link? Matt Ridley is not a scientist. He is a writer and conservative businessman associated with the right wing anti-science group that pretentiously calls itself the Global Warming Policy Foundation.
Earth Observatory has a spectacular picture of NPP liftoff for anyone who might be interested (“Weather and Climate Meet on NPP Satellite”):
More links in attached text.
For ‘Blue Sky’ — Google Scholar for AMSU temperature trend
First result is:
Contribution of stratospheric cooling to satellite-inferred tropospheric temperature trends
David, greatest care possible must be given to achieve exact mass of water, the bigger the size of the flask the likeliest the flasks have different weight and volume as well.. Tap water is also not preferred. Good for you for trying! .. I suggest repeating your samples after cool down to room temp. This would be revealing.
Gavin or a physical chemist, what would be the carbon (# 22) 30 ppm mole ratio of sugar mixed in water given that CO2 has 11 carbon atoms less than sucrose? … I dont think 30 ppm sucrose in water is the same as 360 ppm CO2 in air, although it would be nice… Thanks in advance.. Need it for recipe introduction.
Thank you to the folks who answered my question. I now have some solid stuff to tell him, particularly about standard error. And I’m kind of embarrassed that I didn’t come up with the batting average example on my own.
Pete Dunkelberg @51
The transcript of Ridley’s talk is available on Bishops-Hill or via a link on WUWT.
I’ll leave others to form a view of the talk…I certainly have… the term “oxygen theft” comes to mind.
SkS readers will find it discussed briefly there.
Peter @ 51 – The RSA call him a scientist, you are entitled to your opinion however
#49 Ian, Skeptical science seems to have him sorted out.
The Ridley Riddle Part One: The Red Queen – Skeptical Science
http://www.skepticalscience.com/Ridleyriddle1.htmlThe Ridley Riddle Part One: The Red Queen. Posted on 30 July 2011 by Andy S. This is a three-part series on science writer, businessman and climate …
The Ridley Riddle Part Three: Like a Northern Rock
http://www.skepticalscience.com/Ridleyriddle3.html12 Aug 2011 – The Ridley Riddle Part Three: Like a Northern Rock …
The Ridley Riddle Part Two: The White Queen
skepticalscience.com/Ridleyriddle2.html7 Aug 2011 – The Ridley Riddle Part Two: The White Queen …
#44 blue sky:
Spencer’s Discover page seems to be unreliable, even compared to UAH’s own published satellite temperature timeseries (here: http://vortex.nsstc.uah.edu/data/msu/t2lt/tltglhmam_5.4). The good Dr. does not entertain correspondence on the matter, but it presumably reflects some processing deficiency in the real-time product.
For the record, the UAH LT timeseries currently plots slightly above trend (and very close to GISTEMP when both are re-based to the 1979-2008 means). Available UAH monthlies for this year are:
Vendicar #50, re: John O’Sullivan,
No, the O’Sullivan concerned above would presumably be the Slaying the Sky Dragon author O’Sullivan (b. 1961). The ex-Thatcher-advisor, RFE/RL editor and Hudson Institute fellow O’Sullivan (b. 1942) is a different person, despite vaguely related leanings on climate issues.
There is a story in this, though; the younger John O’Sullivan appears to be padding his resume like crazy, including passing himself off as a National Review columnist on the strength of his elder namesake’s publications. Intelligent conservatives might think that bad form. Personally, as a Buffy fan, I find his pretensions to ‘Slayer’ status even funnier.
“I should clarify for everyone else that Gent et al. 2011 is the model description paper for NCAR’s CCSM4 GCM (more acronym soup).”
Note that they used this procedure only with the 2deg version of CCSM4, which wasn’t used the CMIP5 experiments (and Gent et al. 2011 say they did it “once early on”, which suggests they noticed a large model drift). Even the NCAR doesn’t have enough computational resources to repeat multi-century runs just to find the ones that appear “acceptable”!
Which of Mr Ridley’s points did you find particularly cogent? Addressing all of them would take a long time (and they have been addressed, ad nauseam).
Pete #51, “Matt Ridley is not a scientist, he is a writer”,
True, and it shows in the Galileo/hockey shtick talking points of the Edinburgh talk that Ian (#49) brought up (Bishop Hill has text). But he is a writer of some fairly bestselling popular science books, with a D. Phil. in zoology. Climate change is way out of his usual beat (animal and human behavior), and his understanding of the issue appears to be largely based on a book by some accountant (Montford), based in turn on the blog of a mining consultant (McIntyre). Still, he might be mistaken for someone who knows what he’s talking about, and cheap as his rhetoric is, I imagine it may be effective with audiences.
In response to Robert Murphy (34), CM and others, this may explain why:
John O’Sullivan: Popular Skeptic Writer Fired for Exposing Carbon Climate Fraud
I write to announce my employment with my publishers, Suite101 was terminated today without prior notice or explanation and all my articles published over a two-year period with them are now removed from the Internet. [...]
I write to announce my employment with my publishers, Suite101 was terminated today without prior notice or explanation and all my articles published over a two-year period with them are now removed from the Internet. [...]
He believes this may be in retaliation to his latest post about the “satellite data that contradicts carbon dioxide climate theory”. I would say, a spectacular bit of personal insight. In the blog reply CM mentions O’Sullivan also adds:
Perhaps a Japanese translation of the heading to the graphic would throw some light on this matter.
But perhaps also some verification of what a map says before claiming anything would avoid the need to throw any light in the first place. In any case all the heading states is a date in Japanese format: “Heisei era, 21 July (summer)”, Heisei being the current era.
Thanks Chris and Hank for your comments and links.
Chris wrote: “Warming of the deep ocean waters might be important for these sorts of feedbacks on multi-millennial timescales”
I realize that warming of the deep oceans would take millennia–though I (oddly?) worry about these time scales, too.
But my more immediate concern is for the vast shallow ocean areas such as the East Siberian Arctic Shelf, some 200 million k^2 wide and averaging only 50 m in depth. How much methane is down there and how easily could the warming and increasingly ice-free surface waters melt the frozen methane hydrates on the ocean floor, which, as I understand, cap a much larger reservoir of free methane gas, and which Shakhova has said is destabilizing. Even if it is a relatively minor contributor at this point, how rapidly might feedbacks in these shallow waters amplify?
And to return to the original hypothetical (I hope) question:
If such destabilization does happen at high rates, say an increase by ten fold, how long would it take for the gas to work its way to the rest of the global (or at least Northern Hemisphere) atmosphere, and then how long would it take for this added forcing to make itself fully realized in global temperature changes?
If that is too much to ask, perhaps someone could help me with the broader question:
How long does it take global temperatures to ‘catch up’ to the forcing of ghgs? Are we seeing now the full forcing of CO2 (and other ghgs) emitted up to the point of five years ago? Ten? Twenty?…
Thanks again for your insights and patience.
> CM says: 2 Nov 2011 at 5:25 AM
> Vendicar #50, re: John O’Sullivan,
> No, the O’Sullivan concerned above would presumably be the
> Slaying the Sky Dragon author O’Sullivan (b. 1961). The …
> O’Sullivan (b. 1942) is a different person, despite vaguely
> related leanings on climate issues.
Folks, watch ‘Vendicar’ closely. He can’t be ignored, he’s a mixer. Posting a location and family details of “O’Sullivan” in #50 was bad. Posting the wrong family and location is abysmal. VD creates trouble for other people.
Interesting Observation. Those values are even lower than 2007, at the beginning of the strong La Nina.
A lot of people worry about the very distant timescales, and in fact was the subject of a recent NAS report. It is a very good read and gives a comprehenisive review of the various timescales relevant for future global change.
Solomon S, Battisti D, Doney S, Hayhoe K, Held I, Lettenmaier D, Lobell D, Matthews D, Pierrehumbert RT, Raphael M, Richels R, Root T, Steffen K, Tebaldi C and Yohe G 2010: Climate Stabilization Targets: Emissions, Concentrations and Impacts over Decades to Millennia. National Academy Press:Washington 190pp. Publisher Link
I would read the Brook et al paper I cited in my last comment for a review of methane storage understanding, but my take is that your questions are too uncertain at this point for useful answers. As for timescales, once methane is injected above a shallow ground layer, I see no reason why it can’t make it to the atmosphere rapidly (not necessarily true for deep ocean hydrates), and the methane lifetime in the atmosphere is on the order of ~10 years, which is itself slower than the interhemispheric mixing time (allowing CH4 to be rather well-mixed globally).
As far as global temperatures go, temperatures respond rapidly to increases in greenhouse gases but the system does not relax to a equilibrium point for at least decades, and with some sluggishness on the timescales of centuries. The equilibrium timescale itself also depends on what the “true” climate sensitivity is, which itself is uncertain.
Everyday Fractals vs Extreme Red Herrings and the Climate of the Past
What’s happening? The old climate system is gone. All current weather is produced by the current climate system. The current climate system features much more ocean heat content, warmer sea surface temperatures, warmer lakes, expanded Hadley circulation, less Arctic ice cover, and bunched precipitation (rain and snow more compacted into shorter events). Drought and flood with bunched precipitation in between times and places overall amount to bunched precipitation on a global scale with almost a fractal pattern. The focus on extreme events alone rather than the global pattern is a distraction and something of a red herring isn’t it?
Now consider the statement “The chances are two out of three that climate change has already caused more extreme events.” Only two out of three? Estimate this: what is the chance that an average year of decade under our current climate system would not have more flooding and drought than the same length period on average during 1951-1980? Pending a long model run, if “slim to none” does not come to mind hit me with the clue stick quickly!
Dear RC, would you grant me permission to use a couple or three of your images in a poster or presentation? With attribution of course.
[Response: Not everything is ours to give out. Email me (contrib -at- realclimate.org) with what you want specifically and we'll take it from there. - gavin]
V.D. who posted #50 is wrong. He has the wrong O’Sullivan. The denialist O’Sullivan is nothing to do with Radio Free Europe/Radio Liberty. John O’Sullivan the denialist is a nitwit who (like Lord Monckton and Pat Michaels) has appeared on the Kremlin’s English-language satellite channel “Russia Today.” People who work for RFE/RL tend not to appear on Kremlin mouthpieces. The denialist O’Sullivan seems to be British. He’s some nobody who just makes stuff up.
RFE/RL are very informed journalists and would never have someone like the denialist John O’Sullivan.
RFE/RL writes about climate change and how it affects Russia and the former Soviet Union. Sometimes I give them little tips about climate change issues in Russia.
I got them to write about some Russian “scholar” named Andrei Areshev who claimed that American climate scientists were beaming secret climate weapons at “some countries” (ie Russia) and CAUSING global warming. That happened during the fires.
I told RFE/RL about Areshev and they called him and made him take back his lies about our climate scientists:
Areshev claimed that American scientists are manipulating the climate, but the Russian Academy of Sciences is having a conference right now that seems to be exploring the idea of putting aerosols in the sky to cool the planet. They seem to be looking at the possibility of creating a little nuclear winter.
A really ignorant FBI white paper is giving credibility to a KGB defector who claimed in a book called Comrade J that nuclear winter was a KGB hoax. I told an FBI guy that I am having a little spat with that if the Russians didn’t believe in nuclear winter, they wouldn’t be trying to make one.
Usually I don’t criticise the FBI, but they are being pigheaded.
Realclimate should really cover this Russian Academy of Sciences conference. Hopefully the Russians will decide not to put aerosols in the atmosphere to cool the planet. For one thing, it won’t fix the acidification of the ocean. Alan Robock is going to the conference. Hopefully he will convince the Russians that making a little nuclear winter is probably not a solution to global warming. His talk is called “Smoke and Mirrors.”
Here is some information about the conference. http://legendofpineridge.blogspot.com/2011/10/russian-academy-of-sciences-hosts.html
Here is the English-language version of the conference program.
The Russians will report on their experiments with areosols (making a “controlled” nuclear winter.)
I’m kind of skeptical of easy fixes.
Within an hour or so of reading the latest comments on this thread, I notice that Matthew Ridley’s lecture and John O’Sullivan’s misrepresentation of the Japanese satellite project are being vociferously copied-and-pasted by deniers on blogs everywhere as the latest evidence that the great global warming hoax has been exposed.
It would be funny if it were not so sick.
Referring to Dave Werth’s post about temperature being measured in integral degrees. The statistics of this have been explained by several posters, and are familiar to those of us who actually do measurements. My concern with this comment is the fact that an adult could conceive that an entire community of scientists could miss something so obvious. This expresses a contempt for expertise that is absolutely amazing. Also, it expresses a remarkable intellectual laziness; it would be very easy for this person to look into the way averages affect the errors of measurement. One might actually get to the point of exploring systematic errors, and how standards are maintained in a technological society. If one takes the time to dig a bit, one sees that there are lots of extremely honest people doing all this work, and these people have a level of competence in their disciplines that should be remarkable to the average non-scientist.
I’ve just read the text of the lecture. For me the most important part is that Matthew Ridley is underestimating climate sensitivity and overstating uncertainties in water vapour and cloud feedback, while conflating these issues with (what I consider to be) baseless concerns about very high sensitivity. The Hockey Stick debate is tired and boring, and concentration on the Hockey Stick was not a factor that persuaded me that AGW is likely to be a serious threat.
He is correct that nobody knows for sure whether we’re headed for a disaster if we continue to emit CO2. And he is correct that some overstate the risks. However he is not correct to say it is only models that give cause for concern. Since ditching my scepticism some years back I’ve been left with reading the science as a hobby. I’ve centred my reading on the Arctic as it’s the most exciting area of the science. The potential threats from the Arctic alone are:
*Methane release from permafrost and ocean clathrates.
*Increased mass loss from Greenland’s northern flanks
*Rapid changes in weather and atmosphere/ocean circulation (i.e. climate shifts) due to loss of Arctic sea-ice.
All of these matters are real issues as shown by science based on observations.
If people chose to take the risk and do nothing about CO2 emissions that is their choice. People are free to vote and spend as they see fit (virtually the only countries making what paltry efforts have been made are free-market democracies).
However in making such decisions one must bear in mind the consquences of being wrong. Those who chose to take the risk of doing nothing will have to live with their decision if they are wrong, as indeed will we all.
All I’m saying is, personally I chose not to take the risk.
There is another point from the lecture that’s worth noting at this point – the unfounded alarmism of suggesting we’ll jeopardise our economy over action against CO2 emissions. There is no evidence that any government would seriously consider doing that – it would be political suicide.
Thanks for response. Not sure if 53 is mocking.
What size cold anomalies in global temps would create concern for AGW? Not being an expert..I thought that Co2 trapped heat and that slowly but steady global temps rise.
How long would a stall in rising temps and/or how much a decline over a short period would through current accepted theory into question?
Chris R wrote re: Matthew Ridley’s lecture: “He is correct that nobody knows for sure whether we’re headed for a disaster if we continue to emit CO2.”
No, Ridley is not correct. We are already experiencing destructive and costly disasters caused by the warming that has already occurred from the CO2 that we have already emitted.
And this is exactly why the denialist propaganda machine is going into overdrive to denounce, ridicule and attack anyone who talks about the connection between AGW and the ongoing escalation of unprecedented “weather of mass destruction”.
Chris R wrote: “And he is correct that some overstate the risks.”
Who are these “some” and exactly how are they “overstating” the risks?
And for that matter, considering that the plausible risks of continuing on our present course of ever-increasing GHG emissions include mass extinction of most life on Earth, how exactly can the risks even be “overstated”?
As far as I can tell, Ridley is just another denier spouting whatever talking points he can scrape up to argue against doing anything to reduce fossil fuel consumption. Given his track record in the British banking industry, I can’t imagine why anyone would listen to anything the man has to say.
I’ve skimmed over the PDF file of Matt Ridley’s talk only briefly, concentrating primarily on the physical science points of his presentation. He is very confused, and virtually everything in that section was wrong (which is presumably why the WUWT crowd is eating it up).
Just a few of the many problems
- He confuses the equilibrium climate response with the (expected) transient climate response to the current increase in CO2.
- He improperly dismisses the role of aerosols in offsetting some of the greenhouse warming. He states that the NH warming faster than the SH is evidence against aerosol impacts, since aerosols are located moreso in the North. There are many other factors at play in the N-S asymmetry however, primarily due to the different land-ocean area contrast between hemispheres.
- The rest is full of irrelevant distraction arguments. Climategate, the hockey stick, the irresponsibility of Pachauri on the glacier issue, etc are all interesting to some people, and the skeptical concerns about them have varying degrees of merit, but atmospheric physics does not care about any of this.
Climate sensitivity depends on a lot of things, but whether or not e-mails were hacked into is almost certainly not one of them
[Response: ok, that's it for this topic--no further posts on Matt Ridley, etc. -moderator]
> Not sure if 53 is mocking.
No. The different levels overlap. http://stephenschneider.stanford.edu/Publications/PDF_Papers/FuJohanson2004.pdf Don’t know if there’s a correction at the website you asked about; worth checking.
“Increased levels of carbon dioxide (CO2) in the atmosphere have resulted in the warming of the troposphere and cooling of the stratosphere”
Chris R. says, “If people chose to take the risk and do nothing about CO2 emissions that is their choice. People are free to vote and spend as they see fit (virtually the only countries making what paltry efforts have been made are free-market democracies).”
Let us say, Chris that you own a gas station, and as you are pumping gas, I choose to light up a cigarette. Or let us say that we are in a flimsy rubber lifeboat on the open sea, and I choose to light a fire to warm myself. These actions are my choice to make, after all. Why should you object?
The climate doesn’t care who screws up. The CO2 could be from the US or China or Timbuktou. Our progeny will all suffer just the same.
Ch5 in the data is in the troposphere (14,000 ft).
Harvey @ #73,
The guy is a true believer. Among other things when I mentioned the Isthmus of Panama is around 3 million years old he said geologists have no clue about how old it is and radiometric dating was bogus. I didn’t bother arguing with him about that but the precision of statistics thing was so basic that I wanted to give him a solid answer. I haven’t heard back from him yet.
> Dan H
> Ch5 … is in the troposphere
And you read at least the title of the paper, so you got the point.
Glad of that.
Every climate scientist should know and understand
universities researchers contact vukcevicu(at)yahoo.com
Are you being your usual condescending self, or do you believe that stratospheric influences on the entire troposphere have greatly increased in the past month pushing temperatures lower than previously observed?
#61, doskonaleszare – ‘Note that they used this procedure only with the 2deg version…’
Ah, yes, you’re right. I hadn’t connected those two dots before.
I didn’t think NCAR would be repeatedly performing runs for weeks or months on end until they found one they were happy with, which is why I’m not sure about Rattus’ description of it as a tuning exercise.
Still curious what would be deemed unacceptable though. The paper suggests they were prepared to reject a 1deg run if it was unacceptable, but it just didn’t happen.
RE: “[Response: People are more than welcome to discuss the effect of climate on crop yields in the new open thread as long as they actually stick to the topic, provide legitimate support for their statements that others can check, and steer clear of insults. Believe me, I'm as interested in the topic as anyone.--Jim]”
A climate ‘debate’ without the insults? Certainly an interesting theory, Jim. Shall we test it?
Earlier it was noted that the BEST study was showing about (arguably, to a degree – literally) 2C warming since the 1810′s. Whether it’s 2C or less (or more) doesn’t really matter. There has been (arguably) unprecedented climate change. I was asking whether or not now is seen as ‘better’ climate-wise than the early 1800′s because it’s warmer now. This lead to ‘who decides what’s better’ and from there the ‘debate’ began on whether or not (weather or not?) climate change has already had – and continues to have – an adverse affect on crop yields. Specifically corn yields in U.S. and Canada.
I posted a link to the U.S. Dept of Agriculture’s web site. I chose the parameters of Total Bushels and Bu/Acre. I chose only those 2 so that historical/yearly production could easily be seen and thereby increases and decreases in yields just as easily seen and compared. (One can chose from quite a wide range of stats; to include all or just one of particular interest.) Looking at that data (1860′s – 2011) it clearly shows a steady and significant increase in yearly corn yields. No question. No debate. There is no other way to look at the data or interpret that data. Corn yields have increased steadily and significantly. And climate change is apparently to blame.
What I mean is; there is no evidence that climate change has been a ‘bad thing’ as far as U.S. corn production goes (any other crop?). Why are there still those that will insist that not only has it been a bad thing, it has been a ‘really’ bad thing and include the inevitable ‘it’s worse than we thot’ scenarios.
Here’s a link to the USDA. This one shows yields (Bu/acre) over acres planted. You can see how total acres planted have gone down slightly since the 20′s but the yields have dramatically increased.
True or false: Climate change has been, thus far, beneficial to corn production in the U.S.
[Response: Fair enough, and appreciate you outlining how the discussion proceeded from your vantage point. Yields of most major agronomic crops have increased greatly over the last century, no question, and corn is certainly one of the textbook cases. Because corn is a C4 grass, it tolerates high temperatures better than those that are not (e.g. barley, wheat, oats). However, the mistake you are making is in attributing the increases to climate change alone. It is very well known that much of this increase is due to breeding (the development of hybrid corn lines in particular), and management (fertilization and irrigation in particular). These increases cannot be continuously linear indefinitely, because you will eventually run into a biological yield ceiling (asymptote) which makes each increment of increase harder to achieve than the previous one. You can't just look at what has happened to date and extrapolate it into the future; that's a big mistake in a biological system. That was Ray's point. Also, in order to defend your viewpoint, you will have to provide evidence that climatic changes have been the dominant driver of increases in US corn production--Jim.]
Looking at that data (1860′s – 2011) . . . . And climate change is apparently to blame.
One question > is rising temperature the only variable that has affected agriculture since 1860?? Can we ‘debate’ the influence of mechanization, petro-chemical fertilizer and pest control inputs?
“True or false: Climate change has been, thus far, beneficial to corn production in the U.S.”
False, ask N. Dakota and Manitoba growers what influence climate has had the past few years.
[Response: He was referring to the century time scale. Let's keep it focused there.--Jim]
Your analysis can be extended to most other crops. Thus far, everything has been working to increase yields; longer crowing season (less frosts), greater precipitation, and higher atmospheric CO2 concentrations. The only natural ingredient missing was fertilization, which farmers generously applied.
Similar results have been found for Aspen trees in the experiment in Rhinelander, WI.
[Response: No, your statement is highly simplistic. You've ignored the enormous impact of breeding and biotech for one. And not all climatic changes have been beneficial. Don't make statements without backing them up--I'll delete them.--Jim]
Barn E. Rubble,
To answer your question we would have to assess whether other parameters have remained the same–ceteris paribus. I think you will find the ceteris ain’t paribus. I would also recommend that we look at those areas where the effects of climate change have been notable–e.g. in TX.
Sorry, Barn, life ain’t simple.
barn E. rubble: “Looking at that data (1860′s – 2011) it clearly shows a steady and significant increase in yearly corn yields … Corn yields have increased steadily and significantly. And climate change is apparently to blame.”
Right. Because NO other factors except climate change have had ANY impact on corn yields during the last 150 years. Increased irrigation, increased fertilizer use, plant breeding, and mechanization have NOTHING to do with it.
barn E. rubble wrote: “there is no evidence that climate change has been a ‘bad thing’ as far as U.S. corn production goes (any other crop?)”
Any other crop? It takes really determined willful ignorance to be unaware of the impact of the Texas drought and the midwestern floods on agricultural production.
It’s really hard to refrain from “insults” when
[edit: I know it's hard. Refrain anyway]
I did back up the tree statement with the most recent study. If you want more evidence about the effects of CO2 and vegetation, read this:
[Response: Dan, the subject at hand is how climate changes (and by extension of discussion, other growth factors), have influenced crop yields, with particular emphasis on corn. You linked to an article about the effects of CO2 fert and ozone on aspen in a controlled experiment in Wisconsin. They're not related. Please stick specifically to the topic of the moment, backed with relevant evidence. CO2 fertilization is a topic I know something about, but it's not what we are discussing here.--Jim]
Barn earlier didn’t believe hot temperature extremes (rather than the average temperature) are known to reduce corn and soy yields. I suggest a look at this year’s news:
https://www.google.com/search?q=heat+extreme+corn+soybean+crop for evidence, and a look at
for what’s expected given what we know now.
The same search done for images gets different info; from the first page:
which draws from
Wolfram Schlenkera and Michael J. Roberts – Nonlinear temperature effects indicate severe damages to U.S. crop yields under climate change – Abstract – Proceedings of the National Academy of Sciences of the USA
Here’s a cornucopian response stating the belief technology will prevail:
and a reply to that:
That ‘takvera’ blog drew from and led me to this fellow’s blog — no relation.
He’s written a lot more worth reading:
(Economics, Environment and Agriculture)
Aside– thanks Jim for, when I get badly off topic, deleting and focusing. That improves the topic threads for other readers later.
You contend that: ‘We are already experiencing destructive and costly disasters caused by the warming that has already occurred from the CO2 that we have already emitted.’
From my reading of the science and dabbling with tools like NCEP/NCAR reanalysis I think the following. It was only in the mid 1970s that the CO2 driven warming rose from natural variability to become the dominant factor in the progression of global ave temp (GAT). Since then there has been some indication of an increase in weather disasters, although reporting biasses remain a problem with this. In some regions (e.g. the Mediterranean and Australia’s Murray Darling Basin) the pattern of impacts from AGW is already rising from the envelope of natural variability. However I do not see a global pattern that is strong enough to call a direct link to temperatures and thus conclude that we are seeing the start of a persistent trend of adverse impacts (changes due to modes such as the NAO/AO/PNA/ENSO may not sustain under continued AGW).
That is my view. I am not in denial about AGW I just don’t think the evidence is as strong as you claim – not yet. To be clear I expect the signal of adverse AGW caused weather disasters to continue to rise above the noise of past and current weather. But I am far from convinced that this is happening now to a degree that it is overwhelmingly convincing.
No need to state the bleedin’ obvious. I am aware that we’re all in it together. The fact is that individuals are free to make choices, it is by making such choices that change will be effected by impacting the political and economic worlds. Do you have another way of making the necessary changes?
> another way
Sometimes there has to be.
Amused: There are No Libertarians in Airplanes
ChrisR, other specific events have been linked to global CC as being very unlikely to have occurred without this forcing: Arctic melt, European deadly heat wave of ’03, last years heat wave and fires in Russia. Do you have reason to say these were not made more likely by GW? How many of these attributions does it take before you would consider that a global effect on weather is underway?
Arctic Melt? Click on my name, read my blog. The changes in the Arctic is most of the climate science I read and post on. The Arctic is a special case – regional factors are massively amplifying AGW.
For a start: Can you cite research that shows the 2003 or 2010 European Heatwaves were outside of the envelope of natural variability? Perhaps you can educate me.
The question seems to me to be whether there is a worldwide pattern of extreme weather impacts that are outside the range of pre-AGW variability. In the case of the post 1975 warming – that is clearly outside of natural variability and has no other explanation than human causation – on that issue case closed. Those I consider to be denialists are the ones who play the boring game of ‘it’s not warming’ ‘OK it is, but not so much’ ‘ and anyway it’s because of the sun/natural cycles/whaddeva delete as appropriate.
I do not consider this to be the case for weather impacts globally. The case is not as strong as is the one for the post 1975 global warming. Even in the case of impacts I have listed they are still only just becoming exceptional and the main reason for considering AGW is the factors involved in those weather events. e.g. Australia’s Big Dry.
The problem with your demand for me to refute weather events as having a AGW cause is three-fold. Firstly for most of these events we hear – “the most severe in 50 years”, “the wettest in 100 years” implying that well before the AGW signal emerged from natural variability in the global average temperature similar events were happening. Secondly all weather now has a component of AGW, even the unremarkable. This is because the impacts of AGW, from Thermo/Mesosphere cooling down to surface warming and increase in atmospheric humidity, are present factors. Thirdly; it is for those who are making an assertion to support it with evidence and argument, not to demand I refute it a-priori.
Taking the opposite approach, do you have any reason to believe that they were made more likely? These types of events have occurred throughout history. What makes you think they are more widespread now?
Chris R., OK, ‘splain to me how individual choices are going to develop a new energy infrastrucure–including smart grid, transportation fuel–and deploy it worldwide before it becomes a moot point.
Today’s TNYT has an article on the (under reported) flooding in Cambodia, actually much more serios than in neiboering (and richer) Thailand. The flooding in Cambodia is reported as greater than ever in living memory.
That’s not a very precise estimate of the recurrence time. Does anybody have a decent estimate?
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